I ran into this website while researching other things. They offer
very reasonably priced prebuilt ALIX systems running pfsense.
All you would need to do with one of these to run m0n0wall would be to take it apart to be able to access the CF card, and replace it with one that has m0n0wall on it. At most you would be out another $30 or so to buy a small CF card and reader/writer. Or I suppose it may be possible to upload a m0n0wall image directly to it if pfsense will allow that - perhaps only renaming the m0n0wall image to what pfsense expects would work?
http://nw-ds.com/http://nw-ds.com/shop/firewalls.htmlBasically, these are 3 NIC ALIX - $140, or $175 with wirelesss.
Good source for CF cards and reader/writer cards:
http://www.logicsupply.com/I have no connection to either of these vendors other than buying CF stuff myself from Logic Supply.